Rolling mills



Feb 21, 1967 Filed Feb. 19

D. STUBBS ETAL ROLLING MILLS 4 Sheets-Sheet 1 FIGJ.

\NVENTORS DENNIS STUBBS RONALD DINGWALL BY THEIR ATTORNEY Feb. 21, 1967Filed Feb. 17, 1964 D. STUBBS ETAL ROLLING MILLS 4 Sheets-Sheet 2NVENTQQS DENNIS STUBBS RONALD DINGWALL THEIR ATTORNEY Feb. 21, 1967D.STUBBS ETAL ROLLING MILLS 4 Sheets-Sheec 5 Filed Feb. 17, 1964 34lNvENToRS D ENNIS STUBBS RONALD DINGWALL THEIR ATTQQNEE Feb. 21, 1967 D.STUBBS ETAL ROLLING MILLS 4 Sheets-Sheet 4 Filed Feb. 17, 1964 INVENTORSDENNIS STUBBS RONALD DINGWALL THEIR ATTQQNEY United States PatentOfifice 3,304,758 ROLLING MILLS Dennis Stubbs, Sheffield, and RonaldDingwall, Middlesbrough, England; said Stubbs assignor of onedralf toDavy and United Engineering Company, Sheifield, England, a Britishcorporation Filed Feb. 17, 1964, Ser. No. 345,320 Claims priority,application Great Britain, Feb. 19, 1963, 6,745/ 63 11 Claims. (Cl.72-24(i) This invention relates to rolling mill stands, and particularlyto mechanisms for the adjustment of the roll gap and of the pass line ofsuch stands.

In rolling mills with a succession of mill stands, it is desirable thatthe pass lines of all the stands lie in a common plane. This requirementpresents a problem in that the rolls of different stands in the trainare set at different roll gaps, and, in operation, are subject todiffering degress of adjustment. Because of this, in previous rollingmill stands in which the roll gap is varied by adjusting one of theco-operating rolls relative to the mill housing, the height of the passline of each stand in the train varies with the position of theadjustable roll.

In one aspect the invention provides a rolling mill stand in which afirst of a pair of horizontal work rolls which have their axes in acommon vertical plane, is adjustably mounted for movement, relative tothe housing which carries both work rolls, to vary the roll gap, and inwhich the housing is mounted on a support structure for verticaladjustment relative to that structure.

In a preferred 'form the invention provides a rolling mill standcomprising a pair of horizontal work rolls rotatably mounted in ahousing with their axes in the same vertical plane, the housing beingmounted on a support structure for movement normal to the pass line andthe axes of the rolls, a first of the rolls being adjustable relative tothe housing to vary the roll gap, a first shaft having a first screwthread co-operating with a first nut secured to the foundation structureand a second screw thread co-operating with a second nut secured to thehousing, the first roll being arranged to follow the axial movement ofthe shaft, the pitch of the first thread being half the pitch of thesecond thread, and means for rotating the shaft.

Embodiments of a rod mill stand in accordance with the invention willnow be described, by way of example only, with reference to theaccompanying drawings of which:

FIGURE 1 is a part-sectional end-elevation of a rod mill stand,

FIGURE 2 is a part-sectional view in the direction of the arrow II inFIGURE 1,

FIGURE 3 is a section on the line IIIIII of FIG- URE 2,

FIGURE 4 is a part-sectional view similar to FIGURE 1 and showing amodification, and

FIGURE 5 is a sectional view of a modified form of drive.

In FIGURE 1 a rolling mill housing 11 (of the type described in detailin United States Patent No. 3,217,525), comprises two similar lowerU-shaped housing members 12 (only one of which is shown) in each ofwhich is slidably guided a roll chock 14 rotatably supporting a lowerhorizontal work roll 16. An upper horizontal work roll 18 is rotatablysupported in upper housing members 29 3,3MJ58 Patented Feb. 21, 1195?with its axis in the same vertical plane as the axis of roll 16, andeach of the members 2t) is prestressed to its associated lower U housingmember 12. The lower housing members 12 are secured together by aspreader 22.

The mill housing 11 is supported between four columns 24-, of afoundation frame, with freedom for vertical movement relative to thecolumns. The foundation frame is secured to a bed plate 25 by bolts, oneof which is shown at 26 in FIGURE 2, which is secured to the floor.

The weight of the mill housing is supported by two shafts 28 (only onewhich is "visible in the views shown) and each shaft is provided with ascrew thread at its lower end 30, engaging in a nut 32 secured to across-member 34 of the [foundation frame by a clamp 33, FIGURE 2. Eachshaft 23 is also provided with a screw thread at its upper end 36, andthis thread engages a similar threaded nut 38 in the mill housing. Thethread on the section 30 of the shaft 28 is half the pitch of the threadon the section 36 of the shaft.

A pair of worm wheels 40 (only one of which is shown) are rotatablysupported in casings 42 (secured to the mill housing by bolts, one ofwhich is shown at 43) and each is provided with straight splines in aninternal bore, which splines engage with similar splines on a middlesection 44 of the shaft 28. Each worm wheel 40 is driven by a worm gear46, which gears are secured on a common shaft 45 which is driven by ahand wheel 47.

At is uppermost end each shaft 28 abuts a pad on the chock 14.

The rolls 16 and 18 are symmetrically disposed about a pass line 48 anda rod guide box, generally indicated at 50, is secured to the foundationframe by clamp plates and bolts.

In order that the optimum clearance between the sides of the housing andthe columns of the foundation frame may be obtained regardless of thecumulative effect of manufacturing tolerances, and of wear, co-operatingWedges 52 and 54 areprovided "between one side of the housing and itsco-operating column 24-. These wedges may be adjusted relative to eachother in order to increase or decrease the said clearance. Wedges 53 areprovided engaging opposing faces on the wedges 52 and 54, and the we es53 can be used to release the wedges 52 and 54.

The housing is restrained laterally in the foundation frame by a wing 56(as shown in FIGURE 3) extending from the housing and having a slot 58in which engages a bolt 60 secured to one of the columns 24. Nuts 61 and63 are provided, between which the wing 56 is guided. The slot 58 isopen-ended at the bottom and this allows the housing to be lifted out ofthe foundation frame for maintenance purposes. The bolts 60 are securedto the columns 24 by nuts 62 and blocks 64 welded to the columns.

Means 65, of a conventional form, as for example as described in ourco-pending application No. 35,492/63 (6,354) are also provided for axialadjustment of the rolls relative to one another.

FIGURE 4 which is a section through one of the shafts 28 shows amodified arrangement for mounting the screw 32. The parts whichcorrespond to those in FIGURE 1 have been given like reference numeralsand will not be re-described. The nut 32 is mounted on a thrust bearing66 on a support structure 67, which is mounted by means of trunnions 68in a recessed plate 70 bolted by bolts '71 to the cross-member 34 of thefoundation frame. The

trunnions permit the slight movement of the housing when the screws areadjusted. This arrangement allows the support members 67 to be liftedvertically with the screws 32 and the shafts and thus quickens standchanging as there is no awkward securing means to be removed. Slidingcover plates may be provided to prevent the ingress of mill scale ordirt to these trunnions. The thrust bearings take the load when thescrews are being operated.

Bellows 72 are provided on each shaft between the casing 42 of the wormwheel and the nut 32, to prevent dirt entering the screw thread betweenthe portion and the nut 32. Similar bellows 73 are provided between eachnut 38 and chock 14.

FIGURE 5 shows an alternative means for driving the worm wheels 46. Agear box casing 74 is secured to the mill housing beneath the axial rolladjustment means 65. In this arrangement the worm wheels 46 are carriedon separate shafts 75, 76 so that they may be driven eitherindependently of one another, or together. In this arrangement theright-hand (in the drawing) worm wheel is carried on the shaft 76 whichis hollow, and the lefthand (in the drawing) worm wheel is carried onthe shaft 75 which extends through the shaft 76. A shaft 77 is mountedat one end in bearings 78 in the gear box casing '74, and at the otherend is keyed to a hand wheel 80. The shaft 77 carries a gear wheel 81meshing with a further gear wheel 82 keyed to the shaft 76. A sleeve 83rotatably mounted on a bearing 84 in the gear box casing 74, andsurrounding the shaft 77 carries at one end a further hand wheel and atthe other end carries a gear wheel 86 meshing with a gear wheel 87 keyedto the shaft 75. A plunger 88 is biased by a spring 90 to connect thehand wheels 80 and 85, but can be withdrawn by the knob 91 to disconnectthe hand wheels so that they may be individually rotated to rotate theshafts 75 and 76 respectively.

The gears 81 and 86 respectively further engage gear wheels 92, 93 whichare rotatably carried on a shaft 94 mounted in the gear casing 74, andthe wheels 92, 93 are arranged to drive revolution counters 95.

In operation, the stand is set up with the housing 11 positioned so thatthe rolls 16 and 18 are symmetrically disposed about the pass line 48,the wedges 52 and 54 are adjusted to obtain the optimum clearance (whichmay be zero) between the housing and the columns 24-, and the nuts 32are adjusted so that the rolls are symmetrically disposed about a passline. The clamps 33 are then tightened in place to secure the nuts 32against rotation. The nuts 61 and 63 are then set to locate the housinglaterally. These nuts may also be adjusted to position the appropriategrooves in the rolls in line with the guides.

To adjust the roll gap, the worm gears 46 are driven and this turns theworm wheels which turns the shafts 28. Rotation of the shafts in thesense to screw them downwardly into the nuts 32 cause the chock 14 to belowered, and the housing 11 to be raised. Due to the pitch of the threadon section 30 of each shaft being half of the pitch of the thread onsection 36 of each shaft, when the shafts (and so the roll chock 14 androll 16) :are lowered one unit of length, the housing will be raised twounits of length relative to the shafts, so that the upper roll 18 israised one unit, and the lower roll 16 is lowered one unit relative tothe pass line 48, and their symmetry :about the pass line is maintained.

The foundation frame shown provides support for a :single rolling millhousing, but it will be appreciated that a foundation frame may beprovided having six columns 24, in which case, two mill housings may besupported therein, the foundation frame having centre columns 24 locatedbetween the housings and providing supports common to each housing.Similarly, the foundation frames may be provided with eight or tencolumns 24, supporting three or four rolling mill housings,respectively. This arrangement of a number of mill housing; within acommon foundation frame, facilitates removal of a number of mill standsfrom the mill train with a single lifting operation.

With the arrangement shown, when no rolling load is applied to therolls, the housing 11 will rest with the end fioat of the threads 36taken up in a downward direction, but when sufficient rolling load isapplied, the housing will rise to take up the end float of the threads36 in an upward direction. In an alternative arrangement, roll-balancemeans are provided so that the housing 11 is held at all times in theuppermost position of the end float, relative to the chock 14.

The term pass line as used herein, means a line normal to the planecontaining the axes of the co-operating work rolls, and passing betweenthe rolls through a point, in the said plane, equidistant from theworking surfaces of the rolls.

In accordance with the provisions of the patent statutes, we haveexplained the principle and operation of our invention and haveillustrated and described what we consider to represent the bestembodiment thereof. However, we desire to have it understood that withinthe scope of the appended claims, the invention may be practicedotherwise than as specifically illustrated and described.

We claim:

1. A rolling mill stand comprising a pair of horizontal work rollsrotatably mounted in a housing with their axes in the same verticalplane, the housing being mounted on a support structure for movementnormal to the pass line and the axes of the rolls, a first of the rollsbeing adjustable relative to the housing to vary the roll gap, a firstshaft having a first screw thread cooperating with a first nut securedto the foundation structure and a second screw thread co-operating witha second nut secured to the housing, the first roll being arranged tofollow the axial movement of the shaft, the pitch of the first threadbeing half the pitch of the second thread, and means for rotating theshaft.

2. A rolling mill stand according to claim 1 including a second shaftsimilar to the first shaft, the weight of the housing being supported onthe first and second shafts.

3. A rolling mill stand according to claim 2 in which each of the firstnuts is mounted on thrust hearings on a support member, and the supportmember is mounted on trunnions on a foundation structure, whereby thehousing, the shafts, first nuts, and supporting members may be easilyremoved vertically.

4. A rolling mill stand according to claim 2 including individual drivemeans for rotating the first and second shafts separately, and means forcoupling the drives together.

5. A rolling mill stand according to claim 4 in which each shaft engagesa worm wheel and is axially movable relative thereto, and including wormgears engageable with the worm wheels to rotate the shaft.

6. Apparatus according to claim 1 including means for adjusting theposition of the stand in the direction of the axes of the rolls.

7. Apparatus according to claim 1 in which the housing comprises a pairof U-sectioned lower housing members and a pair of upper housingmembers, carrying the second roll, and secured to the lower housingmembers by prestressed tie bolts.

8. Apparatus according to claim 7 in which the first work roll isrotatably mounted in chocks slidable in the lower housing members andengaged *by the upper ends of the first and second shafts.

9. Apparatus according to claim 1 in which the support structureincludes a plurality of vertically extending columns in which thehousing is guided for vertical movement.

10. A rolling mill stand according to claim 9 including adjustablewedges between the housing and the columns.

11. A rolling mill comprising:

a housing,

a support structure for said housing adapted to permit 5 verticaladjustment of the housing relative to said structure,

a pair of horizontally arranged work rolls forming a roll gap androtatably carried by said housing and having their axes of rotationlying in a substantially common vertical plane,

one roll .of said rolls being adjustably mounted for movement relativeto said housing to vary the roll gap between said rolls, and

means efiectively connecting said one work roll and said housing andconstructed and arranged such that on movement of said one work rollthrough two units of length in one direction relative to the housing,the housing is automatically moved through one unit of length in theopposite direction relative to said support structure.

References Cited by the Examiner UNITED STATES PATENTS CHARLES W.LANHAM, Primary Examiner. G. P. CROSBY, Assistant Examiner.

1. A ROLLING MILL STAND COMPRISING A PAIR OF HORIZONTAL WORK ROLLSROTATABLY MOUNTED IN A HOUSING WITH THEIR AXES IN THE SAME VERTICALPLANE, THE HOUSING BEING MOUNTED ON A SUPPORT STRUCTURE FOR MOVEMENTNORMAL TO THE PASS LINE AND THE AXES OF THE ROLLS, A FIRST OF THE ROLLSBEING ADJUSTABLE RELATIVE TO THE HOUSING TO VARY THE ROLL GAP, A FIRSTSHAFT HAVING A FIRST SCREW THREAD CO-OPERATING WITH A FIRST NUT SECUREDTO THE FOUNDATION STRUCTURE AND A SECOND SCREW THREAD CO-OPERATING WITHA SECOND NUT SECURED TO THE HOUSING, THE FIRST ROLL BEING ARRANGED TOFOLLOW THE AXIAL MOVEMENT OF THE SHAFT, THE PITCH OF THE FIRST THREADBEING HALF THE PITCH OF THE SECOND THREAD, AND MEANS FOR ROTATING THESHAFT.